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Collins S, Maestrini L, Hui FK, Stuart B, Ueland M. The use of generalized linear mixed models to investigate postmortem lipids in textiles. iScience 2023; 26:107371. [PMID: 37575194 PMCID: PMC10415720 DOI: 10.1016/j.isci.2023.107371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 06/26/2023] [Accepted: 07/10/2023] [Indexed: 08/15/2023] Open
Abstract
Human remains are oftentimes located with textile materials, making them a ubiquitous source of physical evidence. Human remains are also frequently discovered in outdoor environments, increasing the exposure to scavenging activity and soft-tissue decomposition. In such cases, postmortem interval (PMI) estimations can be challenging for investigators when attempting to use traditional methods for reconstructive purposes. Lipid analysis is an emerging area of research in forensic taphonomy, with recent works demonstrating success with the detection and monitoring of lipids over time. In this work, generalized linear mixed models (GLMMs) were utilized to perform rigorous statistical analyses on 30 lipid outcomes in combination with accumulated-degree-days (ADD). The results of this study were consistent with recent works, indicating oleic and palmitic acids to be the most suitable lipids in textiles to target for future use as soft-tissue biomarkers of human decomposition. Interspecies differences between humans and pigs were also addressed in this work.
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Affiliation(s)
- Sharni Collins
- Centre for Forensic Science, University of Technology Sydney, 15 Broadway, Ultimo, NSW 2007, Australia
| | - Luca Maestrini
- Research School of Finance, Actuarial Studies and Statistics, The Australian National University, Canberra, ACT 2601, Australia
| | - Francis K.C. Hui
- Research School of Finance, Actuarial Studies and Statistics, The Australian National University, Canberra, ACT 2601, Australia
| | - Barbara Stuart
- Centre for Forensic Science, University of Technology Sydney, 15 Broadway, Ultimo, NSW 2007, Australia
| | - Maiken Ueland
- Centre for Forensic Science, University of Technology Sydney, 15 Broadway, Ultimo, NSW 2007, Australia
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Reggio C, Palmisano E, Tecchiati U, Ravelli A, Bergamaschi RF, Salzani P, Putzolu C, Casati S, Orioli M. GC-MS analysis of soil faecal biomarkers uncovers mammalian species and the economic management of the archeological site "Le Colombare di Negrar". Sci Rep 2023; 13:5538. [PMID: 37016058 PMCID: PMC10073104 DOI: 10.1038/s41598-023-32601-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 03/29/2023] [Indexed: 04/06/2023] Open
Abstract
The identification of the mammalian species based on faecal sediments in modern and ancient environments is the aim of the research of archaeologists, forensic scientists and ecologists. Here, we set up and validated an optimized gas chromatography-mass spectrometry (GC-MS) method, characterized by a time-saving sample preparation protocol, for the simultaneous analysis of faecal biomarkers (6 sterols/stanols and 5 bile acids) in 14 soil samples from the archaeological site of "Le Colombare di Negrar" in northern Italy. Although the archaeological sediment samples examined are numerically exiguous, a comparative reading of our faecal biomarkers findings with new studies on faunal materials collected in the same stratigraphic detail during recent excavation campaigns will allow to better clarify the economic interest of the animal species farmed in the Colombare site (such as bovines, goats, sheep and pigs) and to shed light on the management of breeding. Together with archaeozoological and archaeobotanical analyses, the investigation of faecal biomarkers can increase our knowledge of how ancient local communities exploited natural resources and may allow us to deduce what their impact on the landscape was.
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Affiliation(s)
- Chiara Reggio
- Dipartimento di Scienze dell'Antichità, Sapienza Università di Roma, Rome, Italy
| | - Erika Palmisano
- Dipartimento di Scienze Biomediche, Chirurgiche ed Odontoiatriche, Laboratorio di Tossicologia Forense, Università degli Studi di Milano, Milan, Italy
| | - Umberto Tecchiati
- Dipartimento di Beni culturali e ambientali, PrEcLab-Laboratorio di Preistoria, Protostoria ed Ecologia Preistorica, Università degli Studi di Milano, Milan, Italy
| | - Alessandro Ravelli
- Dipartimento di Scienze Biomediche, Chirurgiche ed Odontoiatriche, Laboratorio di Tossicologia Forense, Università degli Studi di Milano, Milan, Italy
| | - Roberta F Bergamaschi
- Dipartimento di Scienze Biomediche, Chirurgiche ed Odontoiatriche, Laboratorio di Tossicologia Forense, Università degli Studi di Milano, Milan, Italy
| | - Paola Salzani
- Ministero della Cultura, Soprintendenza archeologia, belle arti paesaggio per le Province di Verona, Rovigo e Vicenza, Verona, Italy
| | - Cristiano Putzolu
- Dipartimento di Storia Culture Civiltà, Alma Mater Studiorum Università di Bologna, Bologna, Italy
| | - Sara Casati
- Dipartimento di Scienze Biomediche, Chirurgiche ed Odontoiatriche, Laboratorio di Tossicologia Forense, Università degli Studi di Milano, Milan, Italy.
| | - Marica Orioli
- Dipartimento di Scienze Biomediche, Chirurgiche ed Odontoiatriche, Laboratorio di Tossicologia Forense, Università degli Studi di Milano, Milan, Italy
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Collins S, Stuart B, Ueland M. The use of lipids from textiles as soft-tissue biomarkers of human decomposition. Forensic Sci Int 2023; 343:111547. [PMID: 36608407 DOI: 10.1016/j.forsciint.2022.111547] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 10/13/2022] [Accepted: 12/22/2022] [Indexed: 12/25/2022]
Abstract
The ability to determine the post-mortem interval (PMI) in complex death investigations involving human remains, is a vital task faced by law enforcement. Establishing the PMI in a case can significantly aid in the reconstruction of forensically relevant events surrounding that death. However, due to the complexities surrounding the decomposition of human remains, the determination of the PMI still remains a challenge in some cases. Thus, the identification of biomarkers of human decomposition are an emerging, and essential, area of research. Previous studies have also demonstrated great success in the use of textiles as a host to indirectly capture decomposition by-products. This study reports the successful adaptation and optimisation of an analytical chemical workflow for the targeted analysis of lipids from textiles associated with decomposing human remains using gas-chromatography (GC) coupled with tandem mass spectrometry (MS/MS). This study discusses novel information regarding the complex challenges of matrix effects observed with decomposition samples. In addition, the first lipid profiles obtained from textiles associated with two decomposing human donors from the Australian Facility for Taphonomic Experimental Research (AFTER) using GC-MS/MS are presented.
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Affiliation(s)
- Sharni Collins
- Centre for Forensic Science, University of Technology Sydney, 15 Broadway, Ultimo, NSW 2007, Australia
| | - Barbara Stuart
- Centre for Forensic Science, University of Technology Sydney, 15 Broadway, Ultimo, NSW 2007, Australia
| | - Maiken Ueland
- Centre for Forensic Science, University of Technology Sydney, 15 Broadway, Ultimo, NSW 2007, Australia.
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4
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Stuper-Szablewska K, Rogoziński T, Perkowski J. Contamination of pine and birch wood dust with microscopic fungi and determination of its sterol contents. Arh Hig Rada Toksikol 2017; 68:127-134. [PMID: 28665796 DOI: 10.1515/aiht-2017-68-2924] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 05/01/2017] [Indexed: 11/15/2022] Open
Abstract
Wood compounds, especially sterols, are connected with the level of contamination with microscopic fungi. Within this study, tests were conducted on wood dust samples collected at various work stations in a pine and birch timber conversion plant. Their contamination with mycobiota was measured as the concentration of ergosterol (ERG) by ultra performance liquid chromatography (UPLC). Another aim of this study was to assess the effect of contamination with microscopic fungi on the sterol contents in wood dusts. Analyses were conducted on five sterols: desmosterol, cholesterol, lanosterol, stigmasterol, and β-sitosterol using UPLC and their presence was confirmed using gas chromatography/mass spectrometry (GC/MS). The results of chemical analyses showed the greatest contamination with mycobiota in birch wood dust. We also observed varied contents of individual sterols depending on the wood dust type. Their highest concentration was detected in birch dust. The discriminant analysis covering all tested compounds as predictors showed complete separation of all tested wood dust types. The greatest discriminatory power was found for stigmasterol, desmosterol, and ergosterol.
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Prost K, Birk JJ, Lehndorff E, Gerlach R, Amelung W. Steroid Biomarkers Revisited - Improved Source Identification of Faecal Remains in Archaeological Soil Material. PLoS One 2017; 12:e0164882. [PMID: 28060808 PMCID: PMC5217961 DOI: 10.1371/journal.pone.0164882] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 10/03/2016] [Indexed: 11/24/2022] Open
Abstract
Steroids are used as faecal markers in environmental and in archaeological studies, because they provide insights into ancient agricultural practices and the former presence of animals. Up to now, steroid analyses could only identify and distinguish between herbivore, pig, and human faecal matter and their residues in soils and sediments. We hypothesized that a finer differentiation between faeces of different livestock animals could be achieved when the analyses of several steroids is combined (Δ5-sterols, 5α-stanols, 5β-stanols, epi-5β-stanols, stanones, and bile acids). We therefore reviewed the existing literature on various faecal steroids from livestock and humans and analysed faeces from old livestock breed (cattle, horse, donkey, sheep, goat, goose, and pig) and humans. Additionally, we performed steroid analyses on soil material of four different archaeological periods (sites located in the Lower Rhine Basin, Western Germany, dating to the Linearbandkeramik, Urnfield Period / Bronze Age, Iron Age, Roman Age) with known or supposed faecal inputs. By means of already established and newly applied steroid ratios of the analysed faeces together with results from the literature, all considered livestock faeces, except sheep and cattle, could be distinguished on the basis of their steroid signatures. Most remarkably was the identification of horse faeces (via the ratio: epi-5β-stigmastanol: 5β-stigmastanol + epicoprostanol: coprostanol; together with the presence of chenodeoxycholic acid) and a successful differentiation between goat (with chenodeoxycholic acid) and sheep/cattle faeces (without chenodeoxycholic acid). The steroid analysis of archaeological soil material confirmed the supposed faecal inputs, even if these inputs had occurred several thousand years ago.
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Affiliation(s)
- Katharina Prost
- Institute of Crop Science and Resource Conservation (INRES) – Soil Science and Soil Ecology, University of Bonn, Bonn, Germany
- * E-mail:
| | - Jago Jonathan Birk
- Institute for Geography - Soil Science, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Eva Lehndorff
- Institute of Crop Science and Resource Conservation (INRES) – Soil Science and Soil Ecology, University of Bonn, Bonn, Germany
| | - Renate Gerlach
- Archaeological Heritage Management Rhineland (LVR-Amt für Bodendenkmalpflege im Rheinland), Bonn, Germany
| | - Wulf Amelung
- Institute of Crop Science and Resource Conservation (INRES) – Soil Science and Soil Ecology, University of Bonn, Bonn, Germany
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Affiliation(s)
- Thomas J Bach
- CNRS-IBMP, Université de Strasbourg, Institut de Botanique, F-67000 Strasbourg, France
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Pensec F, Pączkowski C, Grabarczyk M, Woźniak A, Bénard-Gellon M, Bertsch C, Chong J, Szakiel A. Changes in the triterpenoid content of cuticular waxes during fruit ripening of eight grape (Vitis vinifera) cultivars grown in the Upper Rhine Valley. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:7998-8007. [PMID: 25058466 DOI: 10.1021/jf502033s] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Triterpenoids present in grape cuticular waxes are of interest due to their potential role in protection against biotic stresses, their impact on the mechanical toughness of the fruit surface, and the potential industrial application of these biologically active compounds from grape pomace. The determination of the triterpenoid profile of cuticular waxes reported here supplements existing knowledge of the chemical diversity of grape, with some compounds reported in this species for the first time. Common compounds identified in eight examined cultivars grown in the Upper Rhine Valley include oleanolic acid, oleanolic and ursolic acid methyl esters, oleanolic aldehyde, α-amyrin, α-amyrenone, β-amyrin, cycloartanol, 24-methylenecycloartanol, erythrodiol, germanicol, lupeol accompanied by lupeol acetate, campesterol, cholesterol, sitosterol, stigmasterol, and stigmasta-3,5-dien-7-one, whereas 3,12-oleandione was specific for the Muscat d'Alsace cultivar. Changes in the triterpenoid content of cuticular waxes were determined at three different phenological stages: young grapes, grapes at véraison (the onset of ripening), and mature grapes. The results reveal a characteristic evolution of triterpenoid content during fruit development, with a high level of total triterpenoids in young grapes that gradually decreases with a slight increase in the level of neutral triterpenoids. This phenomenon may partially explain changes in the mechanical properties of the cuticle and possible modulations in the susceptibility to pathogens of mature grapes.
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Affiliation(s)
- Flora Pensec
- Laboratoire Vigne Biotechnologies et Environnement EA 3391, Université de Haute Alsace , 33 rue de Herrlisheim, 68000 Colmar, France
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Stong RA, Kolodny E, Kelsey RG, González-Hernández MP, Vivanco JM, Manter DK. Effect of Plant Sterols and Tannins on Phytophthora ramorum Growth and Sporulation. J Chem Ecol 2013; 39:733-43. [DOI: 10.1007/s10886-013-0295-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 04/24/2013] [Accepted: 04/28/2013] [Indexed: 10/26/2022]
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Hart KM, Szpak MT, Mahaney WC, Dohm JM, Jordan SF, Frazer AR, Allen CCR, Kelleher BP. A bacterial enrichment study and overview of the extractable lipids from paleosols in the Dry Valleys, Antarctica: implications for future Mars reconnaissance. ASTROBIOLOGY 2011; 11:303-321. [PMID: 21545270 DOI: 10.1089/ast.2010.0583] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The Dry Valleys of Antarctica are one of the coldest and driest environments on Earth with paleosols in selected areas that date to the emplacement of tills by warm-based ice during the Early Miocene. Cited as an analogue to the martian surface, the ability of the Antarctic environment to support microbial life-forms is a matter of special interest, particularly with the upcoming NASA/ESA 2018 ExoMars mission. Lipid biomarkers were extracted and analyzed by gas chromatography--mass spectrometry to assess sources of organic carbon and evaluate the contribution of microbial species to the organic matter of the paleosols. Paleosol samples from the ice-free Dry Valleys were also subsampled and cultivated in a growth medium from which DNA was extracted with the explicit purpose of the positive identification of bacteria. Several species of bacteria were grown in solution and the genus identified. A similar match of the data to sequenced DNA showed that Alphaproteobacteria, Gammaproteobacteria, Bacteriodetes, and Actinobacteridae species were cultivated. The results confirm the presence of bacteria within some paleosols, but no assumptions have been made with regard to in situ activity at present. These results underscore the need not only to further investigate Dry Valley cryosols but also to develop reconnaissance strategies to determine whether such likely Earth-like environments on the Red Planet also contain life.
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Affiliation(s)
- Kris M Hart
- School of Chemical Sciences, Dublin City University, Dublin, Ireland.
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Schrick K, Cordova C, Li G, Murray L, Fujioka S. A dynamic role for sterols in embryogenesis of Pisum sativum. PHYTOCHEMISTRY 2011; 72:465-75. [PMID: 21315386 DOI: 10.1016/j.phytochem.2011.01.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2010] [Revised: 12/29/2010] [Accepted: 01/07/2011] [Indexed: 05/08/2023]
Abstract
Molecular roles of sterols in plant development remain to be elucidated. To investigate sterol composition during embryogenesis, the occurrence of 25 steroid compounds in stages of developing seeds and pods of Pisum sativum was examined by GC-MS analysis. Immature seeds containing very young embryos exhibited the greatest concentrations of sterols. Regression models indicated that the natural log of seed or pod fr. wt was a consistent predictor of declining sterol content during embryonic development. Although total sterol levels were reduced in mature embryos, the composition of major sterols sitosterol and campesterol remained relatively constant in all 12 seed stages examined. In mature seeds, a significant decrease in isofucosterol was observed, as well as minor changes such as increases in cycloartenol branch sterols and campesterol derivatives. In comparison to seeds and pods, striking differences in composition were observed in sterol profiles of stems, shoots, leaves, flowers and flower buds, as well as cotyledons versus radicles. The highest levels of isofucosterol, a precursor to sitosterol, occurred in young seeds and flower buds, tissues that contain rapidly dividing cells and cells undergoing differentiation. Conversely, the highest levels of stigmasterol, a derivative of sitosterol, were found in fully-differentiated leaves while all seed stages exhibited low levels of stigmasterol. The observed differences in sterol content were correlated to mRNA expression data for sterol biosynthesis genes from Arabidopsis. These findings implicate the coordinated expression of sterol biosynthesis enzymes in gene regulatory networks underlying the embryonic development of flowering plants.
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Affiliation(s)
- Kathrin Schrick
- Keck Graduate Institute of Applied Life Sciences, 535 Watson Drive, Claremont, CA 91711, USA.
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Schrick K, Fujioka S, Takatsuto S, Stierhof YD, Stransky H, Yoshida S, Jürgens G. A link between sterol biosynthesis, the cell wall, and cellulose in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2004; 38:227-43. [PMID: 15078327 DOI: 10.1111/j.1365-313x.2004.02039.x] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
A crucial role for sterols in plant growth and development is underscored by the identification of three Arabidopsis sterol biosynthesis mutants that exhibit embryonic defects: fackel (fk), hydra1 (hyd1), and sterol methyltransferase 1/cephalopod (smt1/cph). We have taken a dual approach of sterol profiling and ultrastructural analysis to investigate the primary defects underlying the mutant phenotypes. Comprehensive gas chromatography GC-MS analysis of hyd1 in comparison to fk reveals an abnormal accumulation of unique sterol intermediates in each case. Sterol profiling of the fk hyd1 double mutant provides genetic evidence that FK C-14 reductase acts upstream of HYD1 C-8,7 isomerase. Despite distinct differences in sterol profiles, fk and hyd1 as well as smt1/cph share ultrastructural features such as incomplete cell walls and aberrant cell wall thickenings in embryonic and post-embryonic tissues. The common defects are coupled with ectopic callose and lignin deposits. We show that all three mutants exhibit a deficiency in cellulose, but are not reduced in pectin and sugars of the cell wall and cytosol. The sterol biosynthesis inhibitors 15-azasterol and fenpropimorph also cause cell wall gaps in dividing root cells and a reduction in bulk cellulose, corroborating that the cell wall abnormalities are due to altered sterol composition. Our results demonstrate that sterols are crucial for cellulose synthesis in the building of the plant cell wall.
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Affiliation(s)
- Kathrin Schrick
- Department of Developmental Genetics, ZMBP (Center for Plant Molecular Biology), University of Tübingen, 72076 Tübingen, Germany.
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12
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13
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Lipids of the roots ofAconitum septentrionale and of their processing wastes. Chem Nat Compd 1996. [DOI: 10.1007/bf01375115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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14
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Abstract
Based on the current literature and on experience gained in the laboratory, a simplified procedure using direct saponification (0.4 M potassium hydroxide in ethanol and heating at 60 degrees C for 1 h) is the most appropriate method for the determination of total cholesterol in foods. Extraction of the unsaponifiable matter with hexane is efficient and no extra clean-up is required before quantification. An internal standard, 5 alpha-cholestane or epicoprostanol, should be added to the sample prior to saponification and, together with reference standards, carried through the entire procedure to ensure accurate results. A significant improvement in cholesterol methodology has been achieved by decreasing the sample size and performing all the sample preparation steps in a single tube. The method has the advantages of elimination of an initial solvent extraction for total lipids and errors resulting from multiple extractions, transfers, filtration and wash steps after saponification. The resulting hexane extract, which contains a variety of sterols and fat soluble vitamins, requires an efficient capillary column for complete resolution of cholesterol from the other compounds present. The development of fused-silica capillary columns using cross-linked and bonded liquid phases has provided high thermal stability, inertness and separation efficiency and, together with automated cold on-column gas chromatographic injection systems, has resulted in reproducible cholesterol determinations in either underivatized or derivatized form. If free cholesterol and its esters need to be determined separately, they are initially extracted with other lipids with chloroform-methanol followed by their separation by column or thin-layer chromatography and subsequently analysed by gas or liquid chromatography. Although capillary gas chromatography offers superior efficiency in separation, the inherent benefits of liquid chromatography makes it a potential alternative. Isotope dilution mass spectrometry has been widely accepted as a reliable analytical method for highly accurate determination of cholesterol in serum and several definitive methods have been reported. The combination of capillary gas chromatography with mass spectrometry has become an excellent approach for the determination of cholesterol in complex mixtures of sterols and tocopherols, providing high resolution with positive identification. When used to determine cholesterol in multi-component foods, spectrophotometric methods have been documented to overestimate significantly the amount of cholesterol owing to the presence of other interfering substances. A re-evaluation of food products should be undertaken using the more specific chromatographic methods to accumulate data that will more accurately reflect the true cholesterol content.
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Affiliation(s)
- M Fenton
- Department of Animal Science, University of Alberta, Edmonton, Canada
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Schuler I, Duportail G, Glasser N, Benveniste P, Hartmann MA. Soybean phosphatidylcholine vesicles containing plant sterols: a fluorescence anisotropy study. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1028:82-8. [PMID: 2207122 DOI: 10.1016/0005-2736(90)90268-s] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The typical plant sterols (sitosterol, stigmasterol and campesterol) were compared with respect to their ability to regulate membrane fluidity of soybean phosphatidylcholine (PC) vesicles. Fluidity changes were monitored by the steady-state fluorescence anisotropy with 1,6-diphenyl-1,3,5-hexatriene as a probe and assigned to a measure of the acyl chain orientational order. Sitosterol and campesterol appear to be the most suitable sterols in ordering the acyl chains of soybean lecithin bilayers, even more efficient than cholesterol, the standard of reference for sterol effects on membranes, suggesting that they play a significant role in the regulation of plant membrane properties. Stigmasterol is shown to be much less active. Cycloartenol, a biosynthetic precursor of plant sterols, increases the acyl chain order with the same efficiency as cholesterol. We also investigated the effects of two unusual sterols, 24-methylpollinastanol and 14 alpha,24-dimethylcholest-8-en-3 beta-ol, which were shown to accumulate in plants treated with fungicides belonging to two important classes, N-substituted morpholines and triazoles, respectively. These two sterols exhibit a behavior very similar to that of stigmasterol. The results are discussed in terms of sterol effects on the molecular packing of soybean PC bilayers.
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Affiliation(s)
- I Schuler
- Départment d'Enzymologie Moléculaire et Cellulaire de l'Institute de Biologie Moléculaire des Plantes (UPR CNRS 406), Strasbourg, France
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